Summary

Aerosols have a strong influence on the present climate, but this influence will likely be reduced over the coming decades as air pollution measures are implemented around the world. At a global level, aerosols have helped to reduce the warming effect from greenhouse gas emissions, and necessary reductions in air pollution may thus make it harder to achieve ambitious global climate and environmental aims, such as the Paris Agreement's 2°C target. Furthermore, the local nature of air pollution means that the impacts of changes to aerosol emissions—on temperature, precipitation, extreme events, and health—are likely to differ widely from one place to another. Model and observational studies are beginning to assess these impacts, particularly the link between aerosols and precipitation, to elucidate the climate effects of cleaning up our air.